M16C62N Datasheet, PDF (112/213 Pages) Renesas Technology Corp – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

Clock asynchronous serial I/O (UART) mode
Mitsubishi microcomputers
M16C / 62N Group (80-pin)
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
(3) Clock-asynchronous serial I/O mode (used for the SIM interface)
The SIM interface is used for connecting the microcomputer with a memory card or the like; adding some
extra settings in UART2 clock-asynchronous serial I/O mode allows the user to effect this function. Table
1.14.8 shows the specifications of clock-asynchronous serial I/O mode (used for the SIM interface).
Table 1.14.8. Specifications of clock-asynchronous serial I/O mode (used for the SIM interface)
Item
Specification
Transfer data format
• Transfer data 8-bit UART mode (bit 2 through bit 0 of address 037816 = “1012”)
• One stop bit (bit 4 of address 037816 = “0”)
• With the direct format chosen
Set parity to “even” (bit 5 and bit 6 of address 037816 = “1” and “1” respectively)
Set data logic to “direct” (bit 6 of address 037D16 = “0”).
Set transfer format to LSB (bit 7 of address 037C16 = “0”).
• With the inverse format chosen
Set parity to “odd” (bit 5 and bit 6 of address 037816 = “0” and “1” respectively)
Set data logic to “inverse” (bit 6 of address 037D16 = “1”)
Set transfer format to MSB (bit 7 of address 037C16 = “1”)
Transfer clock
• With the internal clock chosen (bit 3 of address 037816 = “0”) : fi / 16 (n + 1)
(Note 1) : fi=f1, f8, f32
_______
_______
Transmission / reception control • Disable the CTS and RTS function (bit 4 of address 037C16 = “1”)
Other settings
• The sleep mode select function is not available for UART2
• Set transmission interrupt factor to “transmission completed” (bit 4 of address 037D16 = “1”)
Transmission start condition • To start transmission, the following requirements must be met:
- Transmit enable bit (bit 0 of address 037D16) = “1”
- Transmit buffer empty flag (bit 1 of address 037D16) = “0”
Reception start condition • To start reception, the following requirements must be met:
- Reception enable bit (bit 2 of address 037D16) = “1”
Interrupt request
generation timing
- Detection of a start bit
• When transmitting
When data transmission from the UART2 transfer register is completed
(bit 4 of address 037D16 = “1”)
• When receiving
When data transfer from the UART2 receive register to the UART2 receive
buffer register is completed
Error detection
• Overrun error (see the specifications of clock-asynchronous serial I/O) (Note 2)
• Framing error (see the specifications of clock-asynchronous serial I/O)
• Parity error (see the specifications of clock-asynchronous serial I/O)
- On the reception side, an “L” level is output from the TxD2 pin by use of the parity error
signal output function (bit 7 of address 037D16 = “1”) when a parity error is detected
- On the transmission side, a parity error is detected by the level of input to
the RxD2 pin when a transmission interrupt occurs
• The error sum flag (see the specifications of clock-asynchronous serial I/O)
Note 1: ‘n’ denotes the value 0016 to FF16 that is set to the UART2 bit rate generator.
Note 2: If an overrun error occurs, the UART2 receive buffer will have the next data written in. Note also
that the UART2 receive interrupt request bit does not change.
111